In prior art, surfaces of molded parts produced by means of a 3D printing method, preferably, are treated manually. Thus, such molded parts, for example, are dyed manually, or are impregnated manually. In order to make the surface treatment more efficient, it is known to put the molded parts to be processed into a container, for example, into a dying pot into which also the dye is introduced. Thereby, several molded parts can be dyed, for example, simultaneously. Usually, molded parts produced in a 3D printing method have to be pre- or post-treated prior and after the dying procedure for which purpose also a corresponding container is provided respectively, in which the pre- or post-treatment steps are carried out.
For a series production of molded parts produced by means of a 3D printing method, this approach, however, is not suitable. On the one hand, for achieving a consistent dye result for a plurality of molded parts, it has to be ensured that the composition of the dye is the same for each dyeing process, on the other hand, the molded parts have to be taken out of the container for pre-treatment into the dye container, and from the dye container into the container for post-treatment manually. Further, for all three treatment steps, it has to be ensured that the respective process parameters remain within certain tolerance limits, and, in fact, over long time periods, if a large number of molded parts has to be processed with a consistent result.